Aneurysms are abnormal bulging or weakening of a blood vessel, often an artery, and can have many complications. A bulging of the blood vessel can disrupt or put pressure on surrounding tissues. In the brain, this can result in a variety of side effects, such as impaired vision, impaired speech, impaired balance, etc. Further, the aneurysm creates a volume that is not along the main flow path of the blood through the blood vessel. It therefore can serve as a location for blood to become stagnant and, due to swirling eddy currents, can contribute to the formation of a thromboembolism. If the aneurysm ruptures, they can cause severe internal bleeding.
Aneurysms can be treated externally with open surgery. Such procedures typically involve closing off the entrance or “neck” of the aneurysm with a device such as vascular clamp or a ligature. However, such open surgical procedures can be highly invasive and may lead to trauma to the adjacent tissue and other side effects.
Aneurysms can also be treated through endovascular procedures. In one procedure, detachable lengths of wires (e.g., coils) are inserted into the interior volume of the aneurysm using a catheter. The coils are intended to fill the volume of the aneurysm to decrease the flow of blood into the aneurysm, inducing stagnation of flow and stimulate clotting within the aneurysm. In settings of large cerebral aneurysms, filling of the aneurysm with multiple coils can lead to mass effect that may induce brain swelling and be an independent cause for new symptoms. In another procedure, for aneurysms with a relatively large neck, the adjunctive use of stents assists with the retention of the coils within the aneurysm. This approach has a contraindication to being used when treating ruptured aneurysm, due to the need for additional anti-thrombotic medications. In another procedure, the coils are held in the volume of the aneurysm with a temporary balloon that is inflated in the blood vessel. The balloon is deflated and removed once the mass of coils is secured. In still another procedure, a stent device is placed in the artery to promote flow of blood past the aneurysm. This leads to stagnation of the blood within the aneurysm and thrombosis inside the aneurysm volume. However, a side branch of a main artery in which the stent device is placed may become trapped or “jailed”, which impedes access to the side branch. In other instances, the side branch can become clotted off, possibly causing a stroke. Additionally, such a procedure generally requires the use additional anti-thrombotic medications, which limits the use of such devices in the setting of treatment of ruptured aneurysms. The stent device is generally formed with a relatively tight weave. While the tight weave increases the effectiveness of the stent device in diverting the blood flow, it also impedes or prevents access to the volume of the aneurysm or the jailed artery. In the event that the aneurysm fails to clot, the obstruction of the aneurysm by the stent device prevents the possibility of placing embolic devices inside the aneurysm. Additional procedures such as the placement of additional stents or open surgery may then be required to treat the residual.
All procedures that involve packing the volume of the aneurysm suffer from several common shortcomings. First, it can take many coils of wire to fill the volume of the aneurysm, which is time consuming and increases the time it takes to complete the procedure. Further, the coils may be compacted over time to occupy a smaller percentage of the total volume of the aneurysm. A great enough compaction of the coils can be considered a recurrence of the aneurysm and may require further treatment.
It would be advantageous to provide an improved system and method of treating an aneurysm.